1. Field of the invention
The present invention is generally concerned with clutch release bearings, that is to say the devices designed, in automotive vehicles in particular, to operate on the clutch release device of a clutch to command disengagement of the latter.
2. Description of the prior art
As is known, a clutch release bearing of this kind generally comprises a first member, commonly referred to as the maneuvering member, which is adapted to be acted on by a control member, in practice a clutch release yoke, and a second member, commonly referred to as the drive member, which is adapted to be acted on by the maneuvering member and to act on the clutch release device of the clutch to be operated, in addition to coupling means adapted to provide an appropriate axial connection between said drive member and said maneuvering member.
The present invention is more particularly directed to the situation in which these coupling means consist of an axially acting spring washer which, bearing on a first transverse shoulder provided for this purpose on the maneuvering member, urges the drive member in the axial direction towards a second transverse shoulder, facing the first in the axial direction, also formed for this purpose on said maneuvering member.
This is the case, for example, in at least some so-called self-centering clutch release bearings, that is to say at least certain clutch release bearings in which the drive member is free to move transversely in all directions relative to the maneuvering member, said drive member having an omnidirectional capacity for movement in contact with the second shoulder on said maneuvering member or a bearing member which bears on the latter in the axial direction, this second shoulder being formed, for example, by one side of a transverse flange on said maneuvering member or, inparticular when the latter also comprises an axial sleeve, by one side of a simple collar projecting radially from the sleeve all around same.
This is the case, even more specifically, with self-centering clutch release bearings in which the self-centering action is maintained, in which, when acted on by the appropriately specified axially acting spring washer, the drive member retains between two operations to disengage the clutch, its position relative to the maneuvering member which it occupies after the first such disengagement.
During the assembly of a clutch release bearing of this kind, which is effected by axial engagement of the drive member on the maneuvering member, the axially acting spring washer employed is usually inserted in advance into the drive member so that, as the latter is advanced, it moves along the axial sleeve of the maneuvering member, sliding over this sleeve as such progression advances.
For this axially acting spring washer to apply a predetermined axial load to the drive member when in service, there must be a specified axial distance between the points at which it bears on the maneuvering member and on the drive member.
This is the reason why there is usually provided a specific transverse shoulder adapted to such bearing engagement on the maneuvering member.
In practice, when the maneuvering member comprises an axial sleeve, as mentioned hereinabove, this shoulder is formed on the latter.
However, because of the sliding of the axially acting spring washer on this sleeve during engagement of the drive member on the maneuvering member, said axially acting spring washer is inevitably entrained relative to said sleeve during this engagement and there is thus, on completion of such engagement, an axial offset between the part of the axially acting spring washer concerned and the corresponding shoulder on said sleeve, said part being set back relative to said shoulder.
It is then usually necessary to employ a tool featuring an annular bush which is inserted for this purpose between the drive member and the sleeve of the maneuvering member, so as to press on the axially acting spring washer and push the latter back along said sleeve until it comes into engagement with the shoulder provided for it on the latter.
It is then necessary to provide sufficient annular space between the drive member and the sleeve of the maneuvering member for the insertion of a tool of this kind, which is prejudicial to the overall radial dimension of the assembly. In the radial direction, this space must be all the greater in that the bush of said tool must itself have sufficient thickness in the radial direction to have sufficient mechanical strength.
A general objective of the present invention is an arrangement offering the advantage of reducing this annular space without substantially reducing the mechanical strength of the tool to be employed.